One of the cooler aspects of GSM cellular providers is that your provider and account are mapped onto a SIM card that can be transferred between phones. Once upon a time, I was unfortunate enough to have T-Mobile (the other major U.S. GSM provider after AT&T/Cingular). Their service was generally acceptable around Northern Virginia and pitiful just about everywhere else, blegh! But anyway, that means I have an old GSM phone I can use on AT&T while my iPhone is in for repair.
The tricky bit was unlocking my old Samsung e715 so it would work with providers other than T-Mobile. After a bit of Googling and a bit of trial and error, here are my notes:
- Start up phone with standard T-Mobile SIM card
- Enter *#9998*3323#
- Press the Exit button
- Enter 7 (phone will reboot)
- Enter *0141# and press the Call button
- Turn the phone off and back on
- Enter 00000000
- Turn phone off and start it with the new SIM card inserted
- Enter *#9998*3323#
- Press Exit
- Enter 7 (phone will reboot again)
- Enter *0141# and press the Call button
- Turn phone off and on again
- Main screen should now display "AT&T" instead of "T-Mobile"
Note that the duplicate steps are intentional. Other sites I found claimed that you could start from booting up on the new SIM card, but my phone wouldn't recognize any of the commands unless I ran them on the T-Mobile card first.